1. Field of the Invention
This invention relates to a method and apparatus for optimizing performance of a machine such as a motor, and particularly to an improved method and apparatus for optimizing a control module that controls performance of the machine.
2. Description of Related Art
In the past, optimal values of a characteristic of a control module (namely, parameter values for deciding input-output relationship of the control module) to control a controlled system were determined by experiment at the time of designing or adjusting settings before shipment, assuming a users of a product comprising the controlled system so that the users' characteristics (preference, technique, personality, and use) could be met.
However, with the diversity and advancement of recent technology, the conventional method of deciding optimal values of a characteristic of the control module by experiment becomes difficulty to optimize the control module, and requires a lot of time.
Since personal characteristics or preferences vary from one person to another, the conventional control method cannot provide a characteristic of products which satisfy all users.
In view of the problems described above, there is proposed a para-evolutionary method. In this method, a control apparatus produces a plurality of chromosomes (individuals) by using control parameters of the control apparatus that exert influence on characteristics of a controlled subject or machine and then have some of the chromosomes evolve by a genetic algorithm by selecting excellent chromosomes based upon intention of the user.
In the method that has been proposed, the machine is actually operated with the respective chromosomes that are produced initially and the user evaluates the respective operations to select out undesirable chromosomes (individuals). Characteristics that fit to the user can be obtained in this method. In the above evolutionary computing, individuals of one generation are created, the individuals of the generation are screened to select and leave parent individuals, a group of individuals of the next generation is created by performing crossover or mutation using the parent individuals, and individuals of higher suitability are obtained by repeating the above operation. See U.S. pat. Nos. 6,032,139 and 6,021,369, for example.